Passive thermal Management for High-Temperature Aircraft Actuation Systems

Electronic actuation systems provide many benefits to aircraft such as enhancement of the flexibility of redundancy systems; simplification of power generation and distribution systems; reduction in aircraft weight; and improvement of survivability and maintainability. The high operation temperature of silicon carbide (SiC) electronics allows the power drive electronics (PDE) to be cooled by using vent air in the bays and/or ambient air through the aircraft skin, thus avoiding the use of ECS air. The proposed program will develop a heat pipe with liquid retention as an effective heat spreader for heat rejection. A structured wick will be used to retain liquid at the evaporator so that the heat spreader will continue to function properly for a short period of time while the aircraft is making high-g maneuvers. A water heat pipe prototype will be constructed for performance tests under 1g, -1g and high g conditions. A toluene heat spreader will be designed and proposed to eliminate freezing issues for practical implementation in military and commercial aircraft.